Embodiments of the present invention generally relate to a system and method for image processing, and particularly to a system and method for overlaying a set of coded data on a virtually dissected anatomical structure.
Medical diagnostic imaging systems encompass a variety of imaging modalities, such as x-ray systems, computerized tomography (CT) systems, ultrasound systems, electron beam tomography (EBT) systems, magnetic resonance (MR) systems, and the like. Medical diagnostic imaging systems generate images of an object, such as a patient, for example, through exposure to an energy source, such as x-rays, passing through a patient, for example. The generated images may be used for many purposes. For instance, internal defects in an object may be detected. Additionally, changes in internal structure or alignment may be determined. Fluid flow within an object may also be represented. Furthermore, the image may show the presence or absence of certain features within an anatomical structure. Information derived from medical diagnostic imaging may be applied in many fields, including medicine and manufacturing.
One particular application is in the diagnosis and treatment of cancer. Although there are many different kinds of cancer, they all share a common cause: an uncontrollable growth of abnormal cells. As most cancer cells grow and accumulate, they form a tumor. Medical diagnostic imaging allows various sections of the human body to be examined for cancerous cells and tumors.
A particular type of medical diagnostic imaging used in detecting cancerous growths is tomographic reconstruction. Tomographic reconstruction creates two-dimensional or three-dimensional images from image data projections (such as x-ray projections) generated in an image acquisition system. Data from multiple projections are combined to produce an image representing an object. Often, two-dimensional slices are reconstructed from scans of a three-dimensional object. The two-dimensional slices may be combined to construct a three-dimensional image. These two or three-dimensional images may be viewed by a physician, or other health care practitioners, in search of cancerous growths, for example.
Not all forms of cancerous growths, however, are easily detected using tomographic reconstruction. One such area is that of colorectal cancer. Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that about 105,500 new cases of colon cancer (49,000 men and 56,500 women) and 42,000 new cases of rectal cancer (23,800 men and 18,200 women) will be diagnosed in 2003. Colorectal cancer is expected to cause about 57,100 deaths (28,300 men and 28,800 women) during 2003.
Colorectal cancers are thought to develop slowly over a period of several years. Most colorectal cancers begin as a polyp, which is a mass of tissue that grows into the center of the tube that makes up the colon or rectum. Once a cancer forms in these polyps, the cancer may grow into the center of the colon or rectum. The cancerous polyp may also grow into the wall of the colon or rectum where the cancer cells may grow into blood vessels. From these vessels, the cancer cells may then break away, spreading to other parts of the body.
Although colon cancer is the third most common cancer diagnosed and the second largest cause of cancer related death in the United States, it has been estimated that up to ninety percent of colon cancers may be prevented. Colonic polyps develop slowly and may take years before becoming cancerous. If polyps are found early, they may be removed before they develop into cancer, or if they are already cancerous, they may be removed before the cancer spreads. Thus, one of the keys to preventing colon cancer is screening for potential cancerous polyps. The importance of screening is further magnified because most colonic polyps do not produce any symptoms, and nearly seventy-five percent of people who develop colon cancer have no risk factors for the disease, yielding no warning for the onset of cancer.
One of the tools available to aide in the screening for colon cancer is a virtual dissection. A virtual dissection, much like an actual dissection, is a view of the interior of an anatomical structure after the structure has been cut open. However, the difference between an actual dissection and a virtual dissection is that a virtual dissection is a computer-generated image, and no cutting is necessary. Also, a virtual dissection may be used to view the interior of living tissue. For example, a virtual dissection may be used to view the interior of various human anatomical structures due to the fact that a virtual dissection may be performed using a scan, such as a CT scan.
A virtual dissection may be used to display a lumen of an anatomical structure, such as a colon. A lumen is an interior wall of an object. As an example, if the object were a colon, the virtual dissected view of the colonic lumen would be a two dimensional computerized reconstruction of the scanned colon wall if it were cut open, dissected, and laid flat on a table. A user may observe the virtual dissected image for potentially cancerous polyps.
Currently, however, it is difficult to identify potentially cancerous polyps in a virtually dissected view. In current systems, a user manually inspects the virtual dissection for cancerous polyps without any visual cues as to the various structures of the colon. Hence, cancerous polyps may “blend in” with the background folds and structures of the lumen, causing the polyps to go undetected. Also, a user may not be aware of excess liquid or fecal matter that may be concealing a cancerous polyp. The lack of visual cues in current systems may cause potentially cancerous polyps to go undetected.
Moreover, the time required to interpret a virtually dissected view is typically long due to the fact that such analysis is done by a human observer. Once the virtually dissected view is created, a human interprets the virtual dissection and visually inspects the dissection for structures that may potentially be cancerous polyps. A human is naturally susceptible to error, and inspections may yield false negatives or false positives, resulting in misdiagnosis or unnecessary surgery. Even correct diagnosis is typically long due to the manual, imprecise nature of the analysis.
Therefore, a need exists for a system and method that provides visual cues on a virtual dissected view of the colonic lumen. Such a system and method may be used to increase the probability of locating cancerous polyps and decrease interpretation time.